The Baltimore Pediatric AIDS Clinical Trials Group (BPACTG) was established in 1988 as a collaborative effort between investigators at The Johns Hopkins University and the University of Maryland at Baltimore. As the two predominant sites for care of HIV-infected children in the Baltimore metropolitan area and the state of Maryland, the BPACTG has been the center of nearly all primary and specialized care for the region and has provided access to the most advanced HIV-specific therapy for infants, children, teenagers, and pregnant mothers. Both sites in the BPACTG share the same goals in their clinical service and research: to provide comprehensive care of the highest quality to families affected by HIV; to conduct research into the mechanisms of transmission and pathogenesis of vertically-acquired HIV infection; and to develop and test new therapeutic modalities for the prevention of HIV disease and transmission of HIV infection. The BPACTG investigators participate actively in the ACTG effort, including committees and working groups. concept sheet and protocol development, and protocol administration. The BPACTG has over 50 patients actively participating in ACTU protocols, and 117 have been enrolled during the first 4 1/2 years of activity. The research described herein plans to enroll 35-40 new patients per year during the four years of proposed funding cycle. The proposed research will involve predominantly underserved patients groups: African-Americans and women. Areas of priority for the ACTG are key elements in this proposal. The BPACTG will continue to participate in perinatal trials attempting to interrupt vertical transmission of HIV, and propose additional developmental research into the determinants of perinatal transmission. Development of novel antiretroviral agents will be a priority for the BPACTG in the next four years, linking Phase I/II trials with the proposed pediatric pharmacology core laboratory. Outreach to adolescents with HIV will continue, with efforts directed at identifying infected teenagers and bringing them into the BPACTG care network. Refinement of existing neurodevelopmental assessment tools and development of new testing instruments is incorporated into the clinical core as well as developmental research components. Establishment of an immunology core laboratory and developmental research into immunologic markers of disease progression are proposed. The past five years have established an effective network of researchers and providers in the BPACTG who serve the HIV-infected youth and expectant mothers of this region. This group has the capabilities, organization, and linkages with the community necessary to conduct productive research which will help provide newer, more effective therapies to prevent HIV transmission and to ameliorate the burden of HIV disease in this population.